The pathology of schistosomiasis results primarily from immunologic reactions to the eggs produced by paired worms of the dioecious trematode, Schistosoma. The purpose of this study is to identify the gender-specific and pair-dependent proteins which are antigenic in infected hosts. Monoclonal antibodies will be prepared against these antigens. The monoclonal antibodies will be used as probes for characterization of the antigens. Anatomical localization and structure will be assessed by immunofluorescense techniques. Immunoprecipitation of radiolabeled schistosomal proteins followed by one- and two-dimensional gel electrophoresis will be used for biochemical analysis of the gender-specific and pair-dependent antigens. A description of the molecular differences in gender-specific differentiation and possibly of the biological role of gender-specific and pair-dependent proteins will be pursued. For this purpose the antigens will be purified by immunoaffinity chromatography. The characterized monoclonal antibodies will then be used as probes for identification of the antigens and antigen/antibody complexes associated with granulomas and glomerulonephritis in infected mice. These studies may provide a basis for understanding that pathological development of schistosomiasis. The potential application of monoclonal antibodies as anti-schistosomal agents will be investigated. In vivo experiments in mice can be expected to reveal which proteins of resident worms would be the ultimate target for attack by either an antibody or by toxin-antibody conjugates. The gender-specific and pair-dependent antigenic cross-reactivity between S. mansoni, S. haematobium and S. japonicum will be characterized. The monoclonal antibodies produced against S. mansoni will be tested for recognition of antigenic determinants in the other two species of Schistosoma important to man. Alternatively, S. mansoni immunoaffinity purified antigens will be tested for immunoreactivity with sera of mice infected with S. haematobium or S. japonicum.